\  5  4- 

^  Lc  n. 

[ Front  Mind.  Vol.  IV.  Ho.  13.] 


IV.— THE  RELATION  OF  ATTENTION  TO 
MEMORY. 

By  W.  G.  Smith. 

•I*  J 

It  is  obvious  to  every  one  that  there  are  endless  degrees  of 
certainty  and  security  in  the  knowledge  which  we  have  ac¬ 
quired,  whether  it  be  practical  or  scientific.  Some  things  we 
cannot  help  recollecting:  other  things  pertinaciously  refuse  to 
be  recalled,  or  they  come  into  our  consciousness  only  after  great 
effort.  If  we  try  to  give  an  account  of  the  reasons  why  some 
given  fact  or  experience  has  impressed  itself  on  our  memory,  we 
find  ourselves  at  once  able  to  name  a  large  number  of  factors 
which  may  have  had  some  share  in  bringing  about  the  result. 
Our  memory  may  be  distinct  and  ready  because  our  interest 
was  aroused  when  the  fact  first  became  known  to  us.  We  may 
have  given  special  attention  to  the  fact  apart  from  its  emotional 
character,  or  we  may  have  had  it  presented  to  us  in  a  specially 
vivid  and  intense  form.  It  seems  plain  also  that  the  power  of 
recollecting  will  depend  in  part  on  the  general  physiological 
condition  of  the  individual,  on  the  degree  of  his  health  or 
strength,  at  the  time  when  he  first  acquires  his  knowledge 
as  well  as  at  the  time  when  he  attempts  to  reproduce  it. 

Some  of  the  factors  which  condition  memory  have  already 
been  the  subject  of  important  researches.  One  problem  among 
others  of  which  Ebbinghaus1  has  given  the  solution,  has  been 
that  of  ascertaining  what  effect  the  lapse  of  time  since  learning 
series  of  meaningless  syllables  has  upon  the  ability  subsequently 
to  reproduce  such  series.  A  similar  though  much  simpler 
problem  has  been  studied  by  Wolfe2  in  his  investigation  re¬ 
garding  the  duration  of  our  memory  for  musical  tones.  Recently 
Muller  and  Schumann3  have  studied  the  effects  of  rhythm 
and  other  modifications  of  the  internal  relations  between  the 
syllables  in  series  like  those  used  by  Ebbinghaus.  Evidently 
it  is  to  such  investigations  as  those,  carried  out  according  to 

1  Uber  das  Gedachtnis. 

2  Philosophische  Studien ,  in.  p.  354. 

3  Zeitschrift  fur  Psychologie  und  Physiologie  der  Sinnesorgane ,  vi.  p.  80. 


b 40903 


48 


W.  G.  SMITH: 


the  experimental  method,  that  we  must  look  for  definite  and 
exact  information  regarding  the  conditions  of  memory  and  the 
actual  processes  involved  in  its  working. 

One  of  the  elements  in  memory  of  whose  efficiency  we  are 
sure,  but  whose  exact  function  has  not  yet  been  studied,  is  that 
of  Attention.  It  is  this  problem,  the  relation  of  Attention  to  our 
power  of  associating  and  recollecting  objects  presented  to  con¬ 
sciousness,  that  is  dealt  with  in  the  following  investigation.  It 
was  in  the  course  of  experimental  work  dealing  with  the 
subject  of  Mediate  Association1  that  its  importance  and  the 
need  of  a  separate  study  of  the  problem  became  evident.  My 
aim  has  been  to  isolate  this  factor  and  shew  what  is  the  effect 
when  a  subject  or  observer  submits  himself  for  the  purposes  of 
experiment  to  conditions  which  bring  about  various  forms  of 
distraction.  I  arranged  and  began  the  series  of  experiments 
which  are  here  described  in  the  Leipzig  Institute  for  Experi¬ 
mental  Psychology  in  the  summer  of  1893 :  they  have  been 
carried  on  since  in  the  Physiological  Laboratory,  Oxford,  in  the 
summer  of  18942.  To  all  those  who  have  assisted,  whether  as 
reagents  or  in  giving  advice  and  help,  I  wish  to  express  my 
heartiest  thanks. 

The  method  employed  by  Ebbinghaus  of  repeating  aloud 
series  of  meaningless  syllables  till  they  could  be  said  by  heart 
seemed  inapplicable  to  the  present  problem.  If  it  is  difficult  to 
keep  a  given  state  of  attention  constant  for  short  intervals,  the 
difficulty  could  only  be  heightened  by  the  increase  in  the 
length  of  time  required  for  learning  when  the  attention  is 
distracted.  And  if  the  object  be  to  isolate  the  process  of 
attending  from  the  other  processes  which  normally  enter  into 
the  act  of  memorising,  then  we  must  have  some  means  for 
analysing  the  complex  elements  involved  in  such  a  mode  of 
memorising  as  that  adopted  by  Ebbinghaus.  On  the  other 
hand  the  method  employed  by  Munsterberg  in  his  investigation 
Die  Association  successiver  Vorstellungen 3,  and  elsewhere,  seemed 
capable  of  being  used  for  the  purpose  of  this  investigation. 
The  principle  of  this  method  consists  in  presenting  the  subject 
matter  which  the  reagent  has  to  commit  to  memory  in  such  a 
way  that  he  acquires  a  certain  knowledge  of  it ;  by  noting  the 
number  and  kind  of  errors  committed  in  the  attempt  to 
reproduce  what  has  been  learned  one  obtains  a  measure  of 

1  This  Journal,  in.  N.S.,  p.  289. 

2  A  paper  describing  these  experiments  was  read  before  the  Physio¬ 
logical  Section  of  the  British  Association  for  the  Advancement  of  Science 
at  the  Oxford  meeting,  1894. 

3  Zeitschr.  f.  Psych,  i.  p.  99.  Cf.  Beitrdge  zur  experimentellen  Psy¬ 
chologic,  Heft  iv.  p.  121. 


THE  RELATION  OF  ATTENTION  TO  MEMORY. 


49 


the  strength  and  accuracy  of  the  associations  which  have  been 
formed.  Obviously,  if  the  conditions  under  which  the  subject 
matter  is  presented  remain  constant,  the  total  of  errors  commit¬ 
ted  ought  to  remain  fairly  constant;  there  seems  theoretically 
no  reason  why  the  process  of  learning  should  be  carried  to 
the  point  where  the  memory  becomes  perfect.  The  method 
employed  in  the  following  experiments  is  in  principle  the  same 
as  that  initiated  by  Munsterberg:  in  detail  however  there  are 
many  variations. 

Letters  of  the  alphabet,  presented  in  such  a  way  that 
disturbing  ideas  and  associations  should  not  readily  be  sug¬ 
gested,  formed  the  subject  matter  which  the  reagent  had  to 
commit  to  memory.  They  furnish  a  convenient  and  easily 
variable  material,  and  though  objections,  which  will  afterwards 
be  referred  to,  may  be  made  to  their  use,  yet  practically  it  was 
found  that  they  were  sufficient  for  the  purpose  in  hand.  After 
a  considerable  number  of  experiments  involving  a  trial  of 
various  modifications,  the  following  method  was  adopted  and 
with  slight  changes  employed  in  all  the  experiments  whose 
results  appear  in  the  Tables.  Twelve  letters  arranged  in  three 
lines,  one  above  the  other,  were  written  on  a  card1 :  the  card 
was  placed  on  a  stand  so  that  the  subject  who  sat  close  by 
could  read  the  letters  with  perfect  ease.  Previous  to  the  actual 
experiment  the  part  of  the  room  where  the  reagent  sat  was  in 
darkness ;  by  a  suitable  arrangement  the  person  in  charge  of 
the  experiments  could  illuminate  the  card  for  any  desired 
length  of  time2.  The  time  chosen  for  exposure  was  ten  seconds; 
at  the  close  of  this  interval,  or  in  the  later  experiments  after  a 
pause  of  approximately  two  seconds,  the  subject  was  required  to 
repeat  as  much  as  he  could  remember  of  what  he  had  learned 
while  the  card  was  visible :  this  together  with  his  remarks  was 
then  recorded. 

Perhaps  the  greatest  difficulty  in  the  investigation  lay  in 
the  arranging  of  conditions  which  would  secure  variation  of 
attention  without  involving  any  too  complicated  mental  activity 
on  the  part  of  the  subject.  The  forms  of  distraction  used  must 
be  simple  and  must  at  the  same  time  have  a  distinct  and 
appreciable  effect.  In  various  researches  dealing  with  the 

1  A  copy  of  one  of  the  cards  taken  at  random  may  be  given: — 

b  f  1  g 
s  w  k  r 
t  x  m  d 

2  In  the  first  experiments  the  light  was  furnished  by  a  small  incan¬ 
descent  electric  lamp  :  later  this  was  replaced  by  an  ordinary  gas-burner 
the  supply  of  which  could  be  regulated  at  will.  During  the  actual 
experiment  the  reagent  was  completely  screened  off  from  the  person 
conducting  the  experiments. 


M. 


4 


50 


W.  G.  SMITH: 


relation  of  attention  to  reaction-time,  the  distraction  has  been 
brought  about  by  different  kinds  of  sensory  impression,  such  as 
the  playing  of  music,  the  beating  of  a  metronome,  or  successive 
flashes  of  light.  It  is  plain  however  that  such  a  means  of 
producing  inattention  would  be  of  little  use  here :  the  conflict 
between  a  series  of  sense-presentations  and  the  somewhat  en¬ 
grossing  activity  involved  in  learning  a  combination  of  letters 
would  be  too  one-sided  and  unequal.  In  one  group  of  ex¬ 
periments  a  metronome  was  kept  beating  while  the  experiment 
was  going  on;  the  subjects  however  remarked  that  they  did 
not  notice  the  sounds  at  all  while  learning.  It  was  suggested 
that  by  requiring  the  subject  to  introduce  into  the  regular 
beating  of  a  metronome  which  was  set  agoing  beside  him 
rhythms  of  varying  complexity,  one  could  obtain  distinct 
and  simple  forms  of  distraction.  As  however  no  definite  or 
constant  result  was  obtained  by  this  method,  it  was  aban¬ 
doned  for  the  one  which  was  employed  in  all  the  experiments 
which  are  summarised  in  the  Tables.  According  to  it  the 
activity  involved  in  memorising  is  interfered  with  by  another 
form  of  activity. 

A  distinct  but  not  too  complicated  device  for  securing  what 
one  may  call  mental  distraction  consisted  in  requiring  the 
subject,  while  learning  the  letters  on  the  card,  to  perform  a 
simple  sum  in  addition,  viz.,  that  involved  in  repeating  the 
series  2,  4,  6,  8,...  or  rarely,  when  the  former  series  tended  to 
become  too  mechanically  easy,  the  series  3,  6,  9....  In  order 
that  an  effective  control  over  the  behaviour  of  the  subject 
might  be  secured,  he  was  required  further  to  repeat  the 
numbers  aloud  and  to  make  each  step  in  the  addition  coincide 
with  the  stroke  of  a  metronome  beating  at  the  rate  of  60 — 70 
strokes  per  minute.  In  order  to  compare  the  results  of  this 
form  of  distraction  with  those  gained  when  the  vocal  organ  was 
exercised,  but  the  mental  activity  implied  was  relatively  small, 
the  subject  was  required  in  the  experiments  of  the  next  group1 
to  repeat  with  each  stroke  of  the  metronome  a  simple  syllable 
such  as  la.  The  distraction  caused  by  speaking  was  next 
compared  with  that  caused  by  employment  of  another  set  of 
muscles,  viz.,  those  employed  in  tapping  the  table  with  the 
forefinger,  each  tap  coinciding  with  a  beat  of  the  metronome. 
Lastly  experiments  were  made  in  order  to  gain  a  normal  result 

1  In  order  to  facilitate  reference  to  the  different  sets  of  experiments,  all 
those  involving  one  special  form  of  distraction  are  taken  together  and 
referred  to  as  a  group.  The  groups  are  given  here  in  the  order  in  which 
they  appear  in  the  various  Tables.  Speaking  generally,  we  may  say  that 
in  group  I.  the  distraction  was  mental,  in  group  II.  vocal,  in  group  in. 
muscular. 


THE  RELATION  OF  ATTENTION  TO  MEMORY. 


51 


and  see  the  value  of  reading  alone  without  any  distraction  save 
that  caused  by  the  fact  that  the  metronome  continued  to  beat. 
The  order  in  which  the  distractions  were  introduced  was  varied, 
but  they  were  always  arranged  so  that  before  any  one  of  the 
four  variations  could  recur,  the  other  three  had  been  tried. 
The  rate  of  the  metronome  was  kept  constant  for  each  set  of  four 
experiments,  and  in  each  hour  the  total  number  of  successful  ex¬ 
periments  numbered  four  or  a  multiple  of  four.  When  owing  to 
any  cause  an  experiment  did  not  succeed,  further  experiments 
were  made  until  an  even  number  was  reached :  in  this  way 
there  was  some  guarantee  that  conditions  favourable  or  un¬ 
favourable  to  the  memory  would  affect  all  groups  equally. 
No  attempt  was  made  to  keep  the  interval  between  the  ex¬ 
periments  constant ;  such  a  constancy  seems  by  no  means  so 
necessary  with  this  method  as  it  is  when  an  engrossing  and 
wearying  effort  has  to  be  kept  up  for  a  prolonged  interval. 
In  any  case  the  work  of  recording  the  observations  of  the 
reagent  makes  such  constancy  very  difficult.  No  system  was 
used  in  choosing  the  cards  for  the  experiments;  it  could  only 
be  rarely  and  by  accident  that  different  individuals  had  to 
memorise  the  same  combinations  of  letters  in  the  same  groups. 
Not  more  than  twice  or  thrice  in  all  the  experiments  was  the 
same  card  used  over  again  with  any  one  individual. 

There  are  two  methods  by  which  one  can  numerically 
estimate  the  value  of  the  answers  given  by  the  subjects.  The 
method  of  summing  errors  has  already  been  referred  to.  The 
other  method  consists  in  estimating  the  value  of  what  has  been 
actually  given,  instead  of  paying  attention  only  to  what  has  not 
been  given  or  has  been  given  wrongly.  Each  takes  expressly 
into  account  what  the  other  has  neglected :  with  a  sufficiently 
large  number  of  experiments  the  two  methods  ought  to  give 
similar  results.  The  first  or  negative  method  of  estimation 
does  not  resemble  any  procedure  employed  in  practical  life : 
the  second  or  positive  method,  on  the  other  hand,  relies  on  the 
principle  of  positive  valuation  commonly  employed  in  esti¬ 
mating  the  answers  given  in  examinations. 

In  dealing  with  the  errors  according  to  the  negative  method 
the  following  classification  was  adopted.  The  first  class  (o)  con¬ 
sists  of  cases  in  which  a  letter  is  omitted  which  was  written  on 
the  card,  the  second  ( i )  of  all  cases  in  which  a  letter  is  inserted 
which  ought  not  to  be  present,  whether  that  letter  was  not  on 
the  card,  or  though  upon  the  card  is  wrongly  given  a  second 
time.  In  the  third  class  ( d )  are  included  errors  due  to  dis¬ 
placement  or  disorder,  whether  that  is  owing  to  reproduction  in 
partly  wrong  order,  or  to  complete  ignorance  of  the  position. 
Each  error  has  the  same  weight  attached  to  it  and  counts  1 ; 

4—2 


52 


W.  G.  SMITH  : 


the  total  number  of  errors  gives  a  basis  for  estimating  the  work 
of  the  memory  in  any  instance. 

The  arrangement  of  values  according  to  the  positive  method 
was  more  difficult ;  one  is  liable  indeed  to  the  charge  of 
arbitrariness  in  affixing  any  kind  of  value.  The  following 
classification  however  seems  based  on  a  natural  and  definite 
principle  of  division.  The  letters  which  were  reproduced  were 
arranged  in  three  classes :  (1)  the  letter  named  is  given  in  an 
entirely  wrong  position,  or  its  position  is  quite  unknown : 
(2)  the  subject  has  a  certain  imperfect  knowledge  of  the 
position  and  order;  the  letter  is  put  in  the  right  line,  or  in 
its  correct  place  in  a  group  of  letters  which  is  in  a  wrong 
position :  (3)  when  everything  is  right  as  regards  the  letter,  full 
value  is  given.  Corresponding  to  the  three  degrees  of  correct¬ 
ness,  three  values  are  assigned ;  to  the  letters  of  the  first  class 
is  given  the  value  1,  to  the  third  the  value  3 ;  the  letters  of  the 
second  class  receive  the  intermediate  value  2.  A  perfectly 
correct  answer  then  would  receive  36  marks ;  according  as  the 
answer  is  more  or  less  incomplete  the  total  value  varies.  A 
more  complicated  system  of  valuation,  which  differentiated  more 
exactly  between  the  different  kinds  of  displacement  or  disorder 
included  in  the  second  class,  was  employed  in  the  first  estima¬ 
tion  of  the  results.  A  special  value,  for  example,  was  given 
where  the  order  was  simply  reversed :  then,  however,  the 
question  arises,  what  is  to  be  done  with  a  case  of  reversed 
order  inserted  in  the  wrong  line  ?  All  such  complications  are 
avoided  by  the  division  given  above,  which  is  based  on  a 
perfectly  simple  principle.  As  a  matter  of  fact  the  results 
gained  by  the  two  systems  agree  in  all  essential  points. 
It  happened  not  unfrequently  in  the  earlier  experiments 
that  an  individual  gave  several  letters  in  a  line  without  in¬ 
dicating  whether  he  had  any  recollection  of  their  position  in  the 
line.  After  some  hesitation  I  decided  to  regard  this  lack  of 
positive  information  as  equivalent  to  uncertainty  on  the  part  of 
the  subject  as  to  the  actual  position  of  the  letters.  When  a 
letter  was  wrongly  inserted  or  repeated,  it  was  simply  dis¬ 
regarded  ;  in  the  case  of  repetition  the  benefit  of  the  doubt  was 
given,  and  that  letter  taken  into  account  which  approached 
most  closely  to  the  correct  position.  It  may  be  said  that 
according  to  this  procedure  an  essential  feature  in  the  answer 
is  unjustifiably  neglected.  It  is  plain,  however,  that  if  the 
method  of  positive  valuation  is  to  keep  strictly  to  its  principle 
of  recognising  what  is  actually  correct  in  the  answer,  cases  of 
insertion  cannot  properly  be  taken  into  account.  In  fact,  as 
will  be  seen  from  an  inspection  of  Table  III.  which  gives  an 
analysis  of  the  errors  in  each  group,  these  cases  form  a  pretty 


THE  RELATION  OF  ATTENTION  TO  MEMORY. 


53 


constant,  and  in  most  cases  relatively  unimportant  element  in 
the  total  of  errors.  It  is  however  easy  to  subtract  from  the 
mean  totals  in  Table  IV.  the  average  errors  of  insertion:  the 
result,  it  may  be  remarked,  is  either  to  remove  or  lessen  the 
discrepancies  which  exist  between  the  two  Tables. 

As  was  before  remarked,  the  reproduction  by  the  subject  of 
what  he  recollected  followed  in  the  earlier  experiments  imme¬ 
diately  after  the  illumination  of  the  card  ceased.  The  result  of 
this  arrangement  often  was  that  the  subject,  fearful  lest  all 
should  disappear,  tried  to  give  with  a  rush  what  was  in  his 
consciousness  at  the  moment,  or  seemed  in  perfect  readiness  for 
being  reproduced.  As  this  tended  in  some  measure  to  defeat 
the  purpose  of  the  experiments  by  reducing  the  part  played  by 
memory,  the  mode  of  reproduction  was  changed.  Accordingly, 
in  the  second  division  of  the  experiments  the  subject  was 
required  to  give  what  he  remembered  at  a  signal  which 
followed  two  seconds  later.  This,  it  is  plain,  introduces  a 
new  and  disturbing  factor,  for  the  question  at  once  arises; 
what  is  being  done  in  the  two  seconds  ?  In  order  to  prevent 
further  repeating  and  memorising  during  this  pause  the  subjects 
were  directed  to  continue  the  activity  which  had  during  the 
time  of  exposure  served  as  a  means  of  distraction.  It  may  be 
objected  that  the  original  inequality  of  these  activities  as 
regards  their  ease  of  execution  would  interfere  here  and  cause 
varying  loss  of  memory  during  the  pause:  this  must  be  ad¬ 
mitted,  especially  since  in  the  last  group  there  was  no 
distraction.  But  it  must  be  pointed  out  that  this  inequality, 
so  far  as  our  knowledge  goes,  would  have  its  effect  not  through 
varying  difficulty,  but  mainly  through  the  varying  completeness 
with  which  the  field  of  consciousness  was  occupied  by  the 
activity.  The  amount  of  work  we  do  in  the  interval  between 
learning  a  task  and  reproducing  what  we  have  learned  may 
have  an  effect  on  memory,  but  this  factor,  so  far  as  I  know,  has 
never  been  directly  taken  into  account  and  experimentally 
studied.  Had  a  new  and  uniform  mode  of  occupying  conscious¬ 
ness  been  employed  in  the  pause,  there  would  still  have  been 
possibilities  of  error :  the  reagent  must  suddenly  recollect  and 
start  upon  something  new,  an  effort  whose  difficulty  would  vary 
according  to  the  difficulty  of  the  preceding  effort. 

It  has  not  seemed  necessary  to  give  in  separate  tables  the 
results  of  the  experiments  involving  the  two  different  methods 
of  reproduction.  On  calculating  the  results  separately  it  was 
found  that  the  difference  between  the  two  sets  of  results  was 
not  great  or  important.  There  are  variations  of  course,  not 
merely  in  the  absolute  totals  but  also,  though  seldom,  in  the 
relative  positions  assigned  to  the  groups  in  the  two  divisions. 


54 


W.  G.  SMITH  : 


But  these  variations  seem  to  be  of  the  same  nature  and  extent 
as  those  which  were  found  when  each  half  of  the  experiments, 
furnished  by  the  first  three  reagents  mentioned  in  Tables  II.  III. 
and  IV.  was  calculated  separately  for  each  individual.  That  no 
constant  and  appreciable  factor  is  neglected  by  presenting  the 
results  together  can  be  definitely  shewn.  The  following  Table 
gives  the  mean  of  the  average  values  assigned  to  the  subjects 
in  the  first  (A)  and  in  the  second  (B)  division  of  the  experi¬ 
ments.  The  upper  line  in  each  division  gives  the  results 
obtained  by  the  negative,  the  lower  those  given  by  the  positive 
method.  The  numerals  in  the  first  horizontal  column  designate 
the  groups  in  the  way  already  mentioned ;  the  total  number 
of  experiments  in  each  group,  except  the  third,  is  for  the  first 
division  29.  The  third  group  was  started  later  and  includes 
19  separate  results.  In  the  second  division,  owing  to  a  slight 
irregularity  in  arrangement,  the  numbers  differ  slightly  for  the 
different  groups ;  in  the  first  there  are  33,  in  the  second  and 
third  34,  and  in  the  fourth  33  experiments. 

Table  I. 


I 

II 

III 

IV 

A 

io-o 

11*9 

9-5 

15*3 

8-2 

16-4 

7*55 

21*4 

B 

10T 

11*3 

8-5 

156 

8*0 

176 

7*4 

21*3 

This  Table,  it  ought  to  be  remarked,  contains  the  results  of 
experiments  made  with  the  last  six  subjects  whose  experiments 
are  given  in  the  succeeding  Tables.  The  experiments  made 
with  Wh.,  A.  and  B.,  the  first  three  subjects,  all  involve  a  pause 
of  two  seconds  after  memorising ;  they  differ  however  as  regards 
the  way  in  which  this  pause  was  employed.  Wh.  did  nothing 
during  the  two  seconds,  being  directed  to  remain  perfectly 
passive ;  A.  in  many  cases  forgot  to  carry  on  the  activity  which 
had  served  as  a  means  of  distracting,  but  did  not  attempt 
actively  to  memorise.  B.  on  the  other  hand  fulfilled  the 
directions  with  much  greater  exactness.  The  resemblance  of 
the  results  gained  under  the  various  conditions  gives  ground 
for  believing  that  the  relative  values  assigned  to  the  groups 
represent  constant  and  definite  processes,  and  that  the  slight 
modifications  in  method  do  not  in  any  appreciable  degree 


THE  RELATION  OF  ATTENTION  TO  MEMORY. 


55 


interfere  with  the  main  variations  which  it  was  the  purpose  of 
the  experiments  to  study.  In  Table  II.,  which  is  given 
below,  the  results  are  analysed  according  to  the  first  or 
negative  method.  The  first  vertical  column  contains  the 
letters  which  have  been  used  to  designate  the  different 
subjects.  Under  N  is  given  the  number  of  experiments  made 
by  the  subject  in  each  of  the  four  groups:  the  total  number 
of  his  separate  results  is  thus  got  through  multiplying  this 
number  by  41.  The  character  of  the  various  groups  has  already 
been  described.  Under  a  is  given  the  average  value  of  each 
experiment ;  under  mv  the  mean  variation  of  each  actual 
experiment  from  the  average,  this  figure  being  got  by  adding 
together  all  the  amounts  by  which  each  separate  result  differs 
from  the  average,  and  then  finding  their  mean.  Under  r  is 
given  the  probable  error  of  the  average  a ,  calculated  according 

/  %v2 

to  the  formula  r  =  0’6745  ^ ,  'tv2  being  the  sum  of  the 

squares  of  the  amounts  by  which  each  result  differs  from  the 
average,  and  n  the  number  of  results  concerned.  In  Table  III. 
is  given  the  average  number  of  errors  of  each  reagent  in  the 
three  classes  (o,  i,  d,)  already  described. 


Table  II. 


I 

II 

III 

IV 

N 

a 

mv 

r 

a 

mv 

r 

a 

mv 

r 

a 

mv 

r 

Wh. 

24 

8*8 

2-5 

0*37 

8‘5 

1-75 

0-31 

7-7 

1*8 

0-35 

7-0 

17 

0-28 

A. 

19 

8-3 

1-3 

0-31 

7  3 

1-8 

0*35 

6*7 

1-7 

033 

6*8 

1*5 

0-29 

B. 

22 

10T 

1*5 

0-28 

8-9 

1-2 

0-31 

7-9 

2-0 

0-38 

8-5 

2-2 

0*41 

He. 

15 

93 

1-2 

0-25 

7*7 

2-5 

0*49 

7*4 

2-8 

0-66 

8*7 

1-7 

0*40 

W. 

15 

9-9 

1*4 

0-31 

9T 

2-0 

0-46 

8*2 

1-6 

0-40 

7-4 

1*8 

0-40 

G. 

10 

11-6 

2-1 

0*54 

11-7 

2-6 

0-59 

10-6 

2-5 

0-79 

8-8 

2-0) 

0-53 

M. 

7 

8*6 

0-9 

0-29 

8*4 

1-0 

035 

5-7 

2-5 

0-77 

4-4 

1-6 

0-59 

K. 

8 

11T 

2T 

0*68 

8-75 

0-85 

0-36 

8-75 

1-0 

033 

7-4 

1-6 

0-52 

H. 

7 

9-4 

1*5 

035 

7-8 

1*4 

0-58 

8-6 

1-6 

0-53 

8-0 

1-1 

0*39 

1  The  deviations  from  this  rule  are  so  few  that  they  are  best  given  in  a 
note.  The  following  corrections  should  be  applied  in  Tables  II.  and  IV.: — 
the  number  of  experiments  made  by  He.  W.  G.  in  Group  III.  should  be 
11,  10,  8,  respectively  instead  of  15,  15,  10,  and  by  G.  in  Group  II.  11 
instead  of  10. 


56 


W.  G.  SMITH  : 


Table  III. 


I 

II 

III 

IV 

0 

i 

d 

0 

i 

d 

0 

i 

d 

0 

i 

d 

Wh. 

5-8 

0*9 

2T 

5-2 

1-0 

23 

4-4 

IT 

2-2 

4*2 

0-9 

1*9 

A. 

5*7 

0-9 

1-7 

4-5 

1*2 

1*6 

3-8 

IT 

1*8 

39 

IT 

1-8 

B. 

43 

1-9 

39 

4*0 

1-2 

37 

3-7 

1-4 

2-8 

3  05 

2T5 

33 

He. 

7-7 

0-2 

1*4 

5-9 

0*5 

1*3 

5-2 

IT 

IT 

4-65 

1*65 

2-4 

W. 

6*9 

0-9 

2T 

5-9 

IT 

2T 

5T 

IT 

2-0 

4*0 

0*8 

2-6 

G. 

5-6 

2-9 

3T 

5-0 

32 

3*5 

4-0 

2*7 

39 

3*5 

2T 

32 

M. 

7*6 

0T 

0*9 

6-4 

0*7 

1*3 

33 

1-0 

1*4 

1-7 

1-6 

IT 

K. 

5-9 

1-2 

4*0 

4-0 

0-9 

385 

4-5 

0-9 

335 

2*5 

1*5 

34 

H. 

8*3 

0-55 

0-55 

6-7 

0T 

1-0 

7-6 

0-3 

0-7 

40 

0-4 

36 

In  Table  IV.  are  given  the  figures  representing  the  values 
of  the  different  groups  when  the  results  are  analysed  according 
to  the  positive  method.  The  Table  is  constructed  on  the  same 
plan  as  the  second.  The  amounts  assigned  according  to  the 
three  degrees  of  value  assumed  by  the  positive  method  have 
not  been  summed  up  separately1. 

Table  IV. 


I 

H 

III 

IV 

N 

a 

mv 

r 

a 

mv 

r 

a 

mv 

r 

a 

mv 

r 

Wh. 

24 

15-0 

3*6 

0-62 

16*8 

3*2 

0-55 

19-2 

4-0 

0*72 

20*0 

2-9 

0-49 

A. 

19 

15-8 

34 

0-68 

19-8 

38 

0*76 

21-4 

43 

0-77 

21*2 

32 

0-58 

B. 

22 

15-9 

2-9 

0-53 

18T 

40 

073 

20-4 

3T 

0-57 

27*2 

33 

0*64 

He. 

15 

11-0 

1-6 

0-34 

16-5 

5*9 

1T7 

18T 

4*8 

1*23 

17-9 

2*9 

0-63 

W. 

15 

11-6 

2-5 

0-55 

14*2 

33 

0-75 

17*4 

38 

1-04 

19*9 

39 

0-94 

G. 

10 

13*4 

4-4 

I'll 

14*5 

38 

0-95 

18T 

2-85 

0-82 

20-6 

2-8 

0-88 

M. 

7 

12-0 

2-0 

0-67 

14-7 

23 

0*77 

23  3 

6*4 

1-97 

28-6 

32 

1T4 

K. 

8 

11*5 

34 

1-06 

17T 

2-9 

0-89 

159 

2'1 

0-68 

22-0 

35 

1-05! 

H. 

7 

10-3 

2-2 

0*76 

14-6 

3-4 

1-35 

12-3 

3*2 

0-93 

19-7 

1-8 

0*56  j 

1  It  may  not  be  amiss  to  give  the  figures  representing  the  average 
result  for  all  the  subjects  in  each  group  :  they  present  a  sort  of  typical 
curve.  The  numbers  in  the  upper  and  lower  lines  give  the  results  of  the 
negative  and  positive  analysis  respectively. 

I.  9-7  II.  8*7  III.  7-95 
12-9  16-3  18-5 


IV.  7-4 
21-2 


THE  RELATION  OF  ATTENTION  TO  MEMORY. 


57 


Before  going  on  to  discuss  the  theoretical  value  and  meaning 
of  the  numerical  results  given  in  the  Tables,  I  wish  to  refer 
shortly  to  the  question  how  far  the  methods  of  experimenting 
and  handling  the  results  are  trustworthy.  One  can  judge  best 
of  such  matters  by  presenting  data  such  as  we  have  in  the 
foregoing  tables.  The  question,  for  example,  whether  com¬ 
binations  of  letters  of  the  alphabet  will  not,  when  used  as 
subject  matter  for  memorising,  give  results  too  uncertain  and 
variable  to  allow  of  any  conclusion  as  to  the  actual  processes  of 
association  and  memory,  receives  its  answer  in  the  foregoing 
numerical  analysis.  It  is  difficult  to  see  how  the  regularity  and 
constancy  of  the  numerical  values  can  be  explained  if  the 
method  be  unreliable.  To  say  that  in  a  single  experiment  any 
one  letter  or  combination  of  letters  reproduced  may  be  due  to 
accident  is  true;  to  conclude  that  therefore  the  same  error 
attaches  to  prolonged  series  of  experiments  is  not  justified. 
Nor  does  the  fact  that  the  same  letters  are  employed  more  or 
less  often  during  the  course  of  an  hour  create  a  difficulty :  the 
combinations  of  letters  employed  are  thoroughly  uninteresting, 
and  have  no  tendency  to  remain  fixed  in  memory  after  a 
particular  experiment  has  been  finished.  In  any  case  the 
possible  errors  arising  from  this  cause  will  obviously  distribute 
themselves  over  all  the  groups,  and  disappear  as  the  number  of 
experiments  increases. 

This  last  observation  applies  equally  when  we  consider  the 
errors  due  to  slight  variations  in  the  time  of  exposure,  in  the 
length  of  the  pause,  in  the  rapidity  with  which  the  subjects 
react  to  the  signal  for  reproduction  in  the  various  cases.  That 
different  combinations  of  letters  will  be  learned  with  varying 
ease  or  difficulty  is  also  a  feature  which  necessitates  having  a 
fairly  large  number  of  observations.  Two  practical  sources  of 
error  remain  to  be  mentioned:  first,  the  tendency  to  form 
intelligible  words  out  of  the  letters  presented;  second,  the 
irregularity  with  which  the  distracting  activities  were  carried 
on  during  the  time  of  exposure  and  during  the  pause.  As 
regards  the  first  error,  it  has  to  be  noted  that  with  almost  no 
other  observers  than  A.  and  B.  did  it  make  its  appearance. 
Where  it  does  appear  however,  this  tendency  is  very  annoying ; 
when  once  the  idea  of  forming  intelligible  words  out  of  the 
letters  occurs  to  the  subject,  it  is  very  difficult  to  suppress  it, 
however  much  he  may  wish  to  do  so — in  fact  the  more  he 
wishes  the  more  difficult  is  it.  I  have  excluded  the  cases  where 
this  error  distinctly  endangered  the  result;  in  the  case  of  the 
observer  A.  very  many  experiments  had  to  be  rejected  for  this 
reason.  The  second  error  illustrates  the  difficulty  of  carrying 
out  two  conscious  activities  simultaneously.  Whenever  the 


58 


W.  G.  SMITH  : 


subject  broke  down  during  the  experiment,  for  example,  when 
the  attempt  to  do  the  sum  in  addition  proved  a  complete 
failure,  then  the  experiment  was  stopped.  When  however  the 
irregularity  in  keeping  time  with  the  metronome  and  in  the 
other  processes  was  not  too  great,  the  observation  was  accepted. 
As  the  state  of  mind  during  the  pause  is  not  so  important,  and 
as  it  was  advisable  not  to  disturb  the  reagent  by  insisting  too 
rigidly  that  the  distracting  activity  should  be  carried  on  through 
the  pause,  a  greater  latitude  was  allowed  in  this  respect.  In  all 
cases  however  it  was  understood  that  the  pause  was  not  to  be 
used  for  the  purpose  of  actively  memorising.  The  question 
may  be  raised,  what  happens  when  the  reagent  remains  passive 
during  this  interval  ?  As  far  as  I  can  gather,  a  sort  of  after 
image  of  a  line  or  part  of  a  line  seems  to  be  present ;  it  is  faint 
and  indefinite  in  the  most  of  cases,  and  gradually  fades  away. 

In  order  to  give  opportunity  for  judging  of  the  extent  to 
which  the  averages  of  the  total  errors  and  of  the  positive  values 
given  in  Tables  II.  and  IV.  really  represent  the  actual  observa¬ 
tions,  both  the  mean  variation  and  the  probable  error  have 
been  calculated.  The  former  measures  the  average  extent  of 
deviation  from  the  mean,  and  in  doing  so  naturally  gives  great 
weight  to  a  large  deviation.  One  or  two  such  deviations  occur 
in  almost  every  series,  usually  one  positive  deviation  being 
nearly  compensated  by  an  opposing  negative  deviation :  they 
have  in  every  case  been  included,  and  no  number  has  been 
rejected  because  it  was  unusually  large  or  small.  It  is 
obvious,  however,  that  such  deviations  are  abnormal,  and  that 
the  mean  variation,  which  makes  one  bad  observation  outweigh 
several  good  ones,  does  not  give  any  true  representation  of  the 
character  of  the  deviations ;  the  larger  the  error  is  the  less 
likely  is  it  to  occur.  For  this  purpose  the  probable  error  is  the 
best  guide:  in  it  both  the  extent  of  the  deviations  and  the 
probability  of  their  occurrence  are  taken  into  account :  the 
resultant  figure  r  gives  the  range  on  either  side  of  the  mean 
within  which  the  observations  probably  fall.  With  the  help  of 
the  mean  variation  and  the  probable  error  we  can  compare  the 
results  here  obtained  with  those  given  in  other  researches :  it 
will  be  granted  I  think  that,  comparing  the  extent  of  the 
probable  error  given  in  Tables  II.  and  IV.  with  that  reached  in 
the  observations  of  Ebbinghaus,  or  the  mean  variation  with 
that  which  Oehrn1  finds  in  experiments  similar  to  those  of 
Ebbinghaus,  one  finds  a  sufficient  regularity  and  steadiness  in 
the  values  assigned  by  both  methods  to  the  various  stages  of 
memory. 


1  Experimentelle  Studien  zur  Individualpsychologie. 


THE  RELATION  OF  ATTENTION  TO  MEMORY. 


59 


The  reliability  of  the  positive  method  of  valuation  seems 
confirmed  by  the  close  correspondence  which  the  relative  posi¬ 
tions  assigned  by  it  to  the  various  stages  of  memory  shew  with 
those  indicated  by  the  other  method :  with  few  exceptions  what 
is  proved  to  be  a  weakened  memory  by  one  method  is  likewise 
proved  by  the  other.  With  absolute  values  we  have  here  of 
course  primarily  nothing  to  do;  it  is  the  relative  positions 
assigned  to  the  different  groups  that  is  our  chief  concern. 
That  the  classification  of  values  adopted  in  the  working  of  the 
second  method  is  merely  arbitrary  could  in  no  case  be  reason¬ 
ably  maintained  ;  that  it  is  in  a  high  degree  trustworthy  seems 
proved  not  merely  by  the  constancy  of  the  relative  values  which 
it  assigns,  but  by  the  general  support  which  it  gives  to  the 
negative  method.  The  discrepancies  between  the  two  methods 
which  do  exist  can  in  most  cases,  as  before  remarked,  be 
removed  or  lessened  when  errors  of  insertion  are  taken  into 
account  in  the  second  method  as  well  as  the  first.  The  other 
divergencies  are  only  such  as  might  be  expected,  for  it  is  only 
roughly  that  the  two  methods  supplement  each  other.  This  is 
at  once  apparent  when  the  values  assigned  to  single  experi¬ 
ments  are  considered ;  it  is  only  when  a  larger  number  of 
observations  are  taken  that  the  correspondence  becomes  defi¬ 
nitely  established.  With  respect  to  single  experiments  it  is  the 
second  method  which  gives  the  truer  estimate — truer  in  the 
sense  that  the  relative  positions  indicated  by  it  correspond  more 
closely  to  the  final  relations  of  the  groups  as  established  by 
both  methods  than  do  those  gained  where  the  sum  of  errors  is 
considered. 

In  beginning  experiments  care  was  always  taken  that  the 
subject  should  by  actual  experiments  become  familiarised  with 
the  task  he  was  required  to  perform.  A  considerable  amount 
of  practice  was  gone  through  by  several  of  the  subjects  before 
the  final  experiments  began,  owing  to  the  number  of  tentative 
experiments  that  were  carried  through  at  the  beginning  of  the 
investigation.  That  the  influence  of  practice  and  exercise  can 
not  be  so  great  here  as  in  experiments  where  a  certain  more  or 
less  difficult  task  has  to  be  done  perfectly,  and  to  be  persisted  in 
till  finished,  seems  clear ;  where  the  learning  on  the  other  hand 
is  continued  only  for  a  short  time  with  no  aim  at  final  correct¬ 
ness,  it  is  obvious  that  the  subject  has  far  less  drill  and  that 
there  will  be  less  growth  in  the  facility  of  learning  than  where 
series  of  syllables  have  to  be  learned  by  heart.  And  at  the 
same  time  we  may  expect  that  the  influence  of  weariness  will 
also  shew  itself  much  less  where  a  method  such  as  the  present 
is  used.  As  a  matter  of  fact,  while  one  observer  complained  of 
being  tired  at  the  end  of  an  hour’s  work,  another  was  surprised 


60 


W.  G.  SMITH: 


at  such  a  complaint;  the  others  made  no  remarks  on  the 
subject.  Only  in  regard  to  one  of  the  groups,  the  third,  was 
the  remark  made  that  the  task  seemed  to  become  distinctly 
easier.  That  in  general  there  was  a  gradual  improvement  in 
the  memorising  ability  of  the  subjects  may  be  concluded  from 
an  inspection  of  the  figures  in  Table  I. ;  in  this  Table  however 
the  results  in  the  second  division  shew  the  effect  of  exercise  com¬ 
plicated  with  other  factors.  In  order  to  gain  more  exact  data  I 
have  analysed  separately  the  results  of  the  three  observers  who 
have  furnished  the  longest  series  of  experiments,  the  average 
values  for  the  first  and  second  halves  of  the  series  being 
calculated  for  each  group.  In  some  cases  there  is  a  fall  in 
the  value  of  the  memory :  in  the  majority  of  cases  there  is  a 
rise,  which  however  is  not  specially  conspicuous  in  any  one 
group.  With  reference  to  the  capabilities  of  the  persons  who 
assisted  in  the  investigation,  it  may  be  remarked  that  all  save 
one  are  graduates  or  students  of  philosophy  and  psychology, 
while  three  are  teachers  of  philosophy. 

The  general  features  of  the  results  presented  by  this  in¬ 
vestigation  may  now  be  summed  up.  The  greatest  distraction 
is  that  caused  by  the  activity  involved  in  summation,  while  the 
use  of  the  organ  of  speech  causes  a  smaller,  but  still  distinct, 
disturbance.  The  effort  required  in  tapping  the  table  produces 
generally  a  certain  disturbance :  its  effect  however  is  neither  so 
universal  nor  so  distinct.  These  conclusions  may  be  taken  as 
proved  by  both  methods;  the  negative  method,  in  addition, 
shews  that  the  most  prominent  factor  in  the  weakened  memory 
is  the  diminution  in  the  number  of  letters  retained.  The 
average  number  of  errors  of  displacement  and  of  insertion  is, 
on  the  other  hand,  smaller  and  remains  for  each  group  practically 
constant ;  relatively  those  errors  take  a  larger  place  in  the 
results  of  the  first  and  second  groups  when  we  consider  them  in 
connection  with  the  decreasing  number  of  letters  which  are 
recollected. 

There  can  be  little  doubt  that  the  factor  to  which  we  must 
look  in  interpreting  the  results  of  the  l#St  three  groups  is  that 
on  which  various  psychologists  have  insisted,  viz.,  the  presence 
of  a  motor  element  in  much  of  our  mental  activity.  And  in 
particular  the  loss  of  memory  due  to  the  effort  of  repeating  a 
syllable  in  an  audible  voice  while  one  is  memorising  seems 
caused  by  the  fact  that  the  reading  or  learning  of  any  series  of 
letters  or  words  is  accompanied  normally  by  a  more  or  less 
distinct  articulation,  this  articulation  being  interfered  with  by 
repeating  the  syllable.  To  what  extent  our  memory  or  asso¬ 
ciating  processes  in  any  case  can  act  apart  from  direct  or 
associated  motor  activity  is  a  further  question  which  cannot  be 


THE  RELATION  OF  ATTENTION  TO  MEMORY. 


61 


dealt  with  here.  For  the  interpretation  of  the  present  results 
it  seems  necessary  to  assume  that  this  motor  activity  plays  a 
very  large  part  in  the  formation  of  our  associations.  The  full 
significance  of  this  assumption  can  be  seized  only  when  we 
remember  that  what  the  subject  is  called  upon  to  do  in  all 
cases  is  simply  to  read  the  series  of  letters,  i.e.,  to  let  the  series 
of  visual  objects  which  are  presented  to  him  impress  themselves 
on  his  memory.  Apart  from  experimental  evidence  one  might 
suppose  that  a  series  of  visual  objects  would  associate  them¬ 
selves  together  as  well  as  any  other  series  of  perceptions  or 
sensations.  But,  as  we  see,  when  the  reiterated  articulation  of 
a  syllable  obstructs  the  further  innervation  of  the  articulatory 
mechanism,  the  memory  is  much  worse  than  it  is  where  no 
distraction  is  present,  and  where  the  unskilled  observer  would 
detect  no  process  other  than  that  of  simple  reading.  Such  a 
result  indeed  is  only  a  confirmation  of  the  fact  already  ascer¬ 
tained  by  Pathology  of  the  close  connection  between  sensory 
and  motor  activities,  and  in  particular  between  the  under¬ 
standing  of  words  and  the  ability  to  articulate  them,  or  in  some 
other  way  give  to  them  a  motor  expression. 

These  theoretical  considerations  are  amply  confirmed  by  the 
observations  contributed  by  the  subjects.  They  insist  that  a 
distinct  and  embarrassing  obstruction  is  felt  when  they  attempt 
to  read  over  the  series  of  letters,  an  obstruction  which  is 
specially  marked  at  a  point  where  a  letter  such  as  z  stands, 
whose  pronunciation  is  unusually  difficult.  They  see  the 
letters  and  realise  them  distinctly  as  visual  objects,  but  are  at 
the  same  time  impressed  with  a  sense  of  their  inability  to 
connect  the  letters  and  form  them  into  a  series  which  can  be 
remembered.  And  they  notice  how  in  the  intervals  of  audible 
articulation  the  attempt  is  involuntarily  made  to  insert  an 
inaudible  articulation,  to  employ  Bewegungs-antriebe,  which 
shall  help  to  form  the  letters  into  a  connected  whole. 

An  additional  support  is  lent  to  this  explanation  by  a 
consideration  of  the  data  presented  by  the  third  group  of 
experiments.  The  object  of  this  group  was  to  allow  of  a 
comparison  between  the  motor  activity  of  the  vocal  organ  and 
that  involved  in  the  use  of  a  set  of  muscles  not  directly 
connected  with  any  mental  operation.  That  an  exact  com¬ 
parison  is  hardly,  if  at  all,  possible  is  plain  from  the  fact  that  we 
must  in  any  case  employ  two  quite  different  groups  of  muscles 
habituated  to  different  functions.  Apart  from  theoretical  ex¬ 
actness  however,  a  basis  for  comparison  may  be  got  by  observing 
what  effect  activity  of  the  vocal  mechanism  has  as  compared 
with  that  implied  in  moving  the  forefinger.  Possibly  the  act  of 
saying  ‘  do  ’  or  *  la  ’  is  more  complicated  than  that  of  moving 


62 


W.  G.  SMITH  : 


* 

the  forefinger ;  yet  after  all  a  very  considerable  degree  of 
facility  in  executing  more  complicated  vocal  movements  must 
be  granted  to  most  persons.  We  may  then  assume  equivalence 
between  the  two  kinds  of  movements  to  this  extent  at  least, 
that  regarded  physically  the  energy  expended  and  the  effort  of 
innervation  required  in  the  two  cases  are  fairly  similar. 

In  almost  every  instance  mere  muscular  movement  produces 
less  of  a  disturbance  in  memory  than  does  activity  of  the  vocal 
mechanism.  And  the  reason  for  this  is  evident:  the  articula¬ 
tory  innervations  involved  in  memorising  are  most  conspicuously 
interfered  with  by  conflicting  activity  of  the  vocal  mechanism. 
The  observations  made  by  the  reagents  are  only  a  concrete 
expression  of  this  statement:  what  they  notice  in  the  ex¬ 
periments  of  the  third  group  is  a  conflict  of  two  motor  series 
such  as,  for  example,  is  involved  in  the  effort  to  play  on  a 
musical  instrument  when  one  hand  is  required  to  move  in  a 
time  different  from  that  of  the  other.  Had  the  reagents  been 
able  to  render  the  two  series  coincident,  and  make  the  rhythm 
of  the  finger  movement  the  same  as  that  of  the  articulatory 
movement,  then  the  difficulty  would  have  been  lessened,  and  one 
impulse  or  innervation  would  have  served  to  carry  out  both 
movements.  But  owing  to  the  arrangement  of  the  experiments 
such  coincidence  would  have  made  the  learning  too  fast  or  too 
slow ;  too  fast  if  a  whole  line  was  to  be  gone  through  at  each 
stroke  of  the  metronome,  too  slow  if  only  one  letter  was  to 
accompany  each  stroke.  In  some  cases  indeed  the  observers 
seemed  to  find  a  help  in  the  rhythm  of  the  finger  movements ; 
when  they  succeeded  in  combining  the  innervations  for  articula¬ 
tion  and  for  movement  an  added  emphasis  was  lent  to  the 
letters,  which  seemed  to  help  in  fixing  them  in  the  memory.  It 
is  evident  however  that  experiments  directed  to  the  isolation 
and  direct  proof  of  this  fact  are  needed  before  anything  definite 
can  be  said. 

If  the  series  of  letters  presented  to  the  reagent  were 
associated  as  visual  objects,  then  it  would  be  still  more  difficult 
than  in  the  experiments  of  the  second  group  to  understand  why 
an  indifferent  muscular  activity,  such  as  that  of  the  hand, 
should  interfere  with  the  associations.  It  may  be  said  that 
this  activity  implies  a  certain  degree  of  inattention  to  the 
letters  presented,  and  no  doubt  this  is  true.  But  the  dimi¬ 
nution  of  attention  must  have  been  very  small ;  there  is  a 
distraction,  but  it  is  almost  wholly  a  distraction  of  the  motor 
mechanism.  And  it  is  important  to  distinguish  here  between 
these  two  things,  predominance  of  a  state  of  consciousness  or 
attention,  and  that  state  or  attitude  of  mind  which  we  term 
activity.  In  many  of  its  manifestations,  and  here  in  particular, 


THE  RELATION  OF  ATTENTION  TO  MEMORY. 


63 


psychical  activity,  so  far  as  it  is  a  factor  different  from  mere 
movement  of  ideas,  seems  intimately  connected  with  some  form 
of  function  of  the  motor  system. 

According  to  the  testimony  of  more  than  one  subject,  the 
disturbance  caused  by  the  finger  tended  to  disappear  in  pro¬ 
portion  as  the  effort  required  to  make  its  movement  keep  time 
with  the  beating  of  the  metronome  became  more  automatic. 
This  would  mean  that  the  two  motor  series  conflict  and  compete 
with  each  other  only  so  long  as  they  both  remain  in  direct 
connection  with  conscious  experience :  two  disparate  activities 
on  the  other  hand  can  be  carried  on  simultaneously  if  one  at 
least  be  automatic,  or  carried  on  apart  from  our  ordinary 
consciousness.  Binet  concludes,  as  the  result  of  an  experi¬ 
mental  study  of  such  questions1,  that  an  automatic  movement 
is  able  to  coexist  with  a  voluntary  movement  because  it  is  not 
preceded  by  a  conscious  mental  representation,  and  consequently 
does  not  involve  conflict  of  ideas.  This  it  is  obvious  is  not  an 
explanation,  but  simply  a  restatement  of  facts :  why  two  con¬ 
scious  series  of  ideas  must  conflict  is  not  explained  either 
psychologically  or  physiologically.  The  theory,  that  inability  to 
attend  effectively  to  more  than  one  series  of  ideas  is  due  to  a 
limitation  in  the  available  psychophysical  energy,  does  not  seem 
at  all  convincing,  but  what  should  be  put  in  its  place  is  by  no 
means  equally  clear. 

It  will  be  observed  that  while,  with  regard  to  the  majority 
of  the  observers  and  the  average  of  the  results  given  by  all 
the  individuals,  the  value  of  memory  shews  a  diminution 
in  the  experiments  of  the  third  group  as  compared  with  the 
fourth,  yet  divergencies  occur.  For  this  fact  various  explana¬ 
tions  are  available.  Apart  from  accidental  variation  in  the 
results,  which  is  not  a  probable  explanation,  there  will  evidently 
be  a  difference  in  the  effect  of  these  distractions  upon  memory 
according  as  the  subject  is  of  a  motor,  a  visual,  or  an  auditory 
type.  I  feel  inclined  to  believe  that  this  is  partly  the  expla¬ 
nation  of  the  irregular  results  of  He. ;  this  individual  was 
particularly  emphatic  in  his  statements  as  to  the  prominence  of 
visual  images  in  the  process  of  reproduction.  How  far  this 
explanation  can  be  carried  is  however  doubtful ;  I  tried  to 
ascertain  from  the  subjects  what  their  usual  kind  of  imagery 
was,  and  to  relate  it  with  the  results,  but  was  not  able  to  find 
any  definite  connexion :  to  establish  such  a  relation  it  would  be 
necessary  to  ascertain  by  direct  experiment  to  what  extent  and 
in  what  relations  the  imagery  conformed  to  the  different  types. 

1  Revile  Philosophique ,  xxix.,  “La  concurrence  des  etats  psychologi- 

ques.” 


64 


W.  G.  SMITH  : 


Another  explanation  may  perhaps  be  found  in  the  fact  that  the 
reagents  were  left  entirely  free  in  their  method  of  learning; 
they  could  learn  the  series  slowly,  or  they  could  run  over  the 
letters  quickly  and  often:  especially  in  the  fourth  group  was 
there  scope  given  for  the  varying  preferences  of  the  individual. 
In  the  other  groups  the  subject,  it  is  plain,  had  to  memorise  not 
so  much  as  he  wished,  but  as  best  he  could.  These  individual 
variations  may  take  shape  also  in  another  form ;  according  to 
his  momentary  disposition  he  will  tend  to  spend  greater  or  less 
energy  in  learning  what  is  presented  to  him.  And  apart  from 
this  general  variability  there  are  the  differences  which  arise 
from  the  fact  that,  as  the  experiments  were  actually  arranged,  a 
severe  distraction  alternated  with  one  less  severe,  or  with  a 
state  of  freedom  from  distraction.  The  subject  will  obviously 
feel  relieved  when  an  easy  task  is  put  before  him ;  this 
however  leaves  it  quite  undecided  whether  he  will  shew 
this  feeling  of  relief  in  memorising  much  better,  the  energy 
expended  being  the  same  as  before,  or  whether  he  will  un¬ 
consciously  with  the  removal  of  the  difficulty  lessen  the  intensity 
of  his  efforts  and,  sure  of  learning  in  any  case  more  than  before, 
will  content  himself  with  memorising  less  vigorously.  These 
divergencies,  it  is  plain,  furnish  the  point  of  departure  for 
further  research  and  exacter  analysis.  In  particular  it  would 
be  desirable  in  a  more  advanced  stage  of  this  research  that 
the  conditions  of  experiment  should  be  altered  so  that  while 
becoming  more  artificial,  they  would  still  in  the  end  be  more 
precise.  A  greater  similarity  in  the  method  of  learning  would 
in  part  be  secured  by  the  adoption  of  a  method  like  that  of 
Muller  and  Schumann,  which  secures  that  each  object  shall  be 
presented  to  the  reagent  in  an  order  and  for  a  length  of  time 
which  can  be  exactly  regulated1. 

In  order  to  facilitate  the  analysis  of  the  various  phenomena 
I  have  begun  by  discussing  the  nature  of  the  processes  involved 
in  the  experiments  of  the  last  three  groups.  It  is  however  only 
in  the  first  group  that  we  have  facts  bearing  directly  and 
immediately  on  the  phenomena  of  attention.  In  fact  the  three 
last  groups  were  arranged  in  order  to  analyse  and  illustrate  the 
factors  that  are  involved  in  the  processes  of  the  first  group. 
That  we  have  in  this  group  a  real  disturbance  of  attention 
might  be  supposed  on  theoretical  grounds ;  that  such  a  state  of 
mind  actually  resulted  from  the  experimental  conditions  was 

1  The  series  of  meaningless  syllables  used  in  their  experiments  were 
written  on  sheets  of  paper;  these  were  fastened  on  a  cylinder  which 
rotated  at  a  known  rate  and  shewed  the  syllables  in  succession  to  the 
reagent,  who  was  looking  through  a  slit  in  a  screen  set  before  the 
cylinder. 


THE  RELATION  OF  ATTENTION  TO  MEMORY. 


65 


asserted  by  the  observers.  The  movements  of  speaking,  said  K., 
one  of  the  most  skilled  observers,  do  not  become  more  difficult 
in  the  fpuffh  group ;  what  the  addition  does  is  to  diminish  the 
energy  available  for  learning. 

Here  again,  as  in  the  relation  between  the  second  and  third 
sets  of  experiments,  it  is  not  possible  to  effect  an  exact 
comparison  between  the  effort  of  articulation  in  the  second 
group  with  that  implied  in  the  repeating  the  series  of  numbers 
audibly.  The  words  uttered  in  the  course  of  the  addition  differ 
with  each  stroke  of  the  metronome :  towards  the  end  of  the 
period  of  memorising  words  of  more  than  one  syllable  are 
involved.  As  regards  the  first  point,  it  is  not  probable  that 
the  effort  of  repeating  different  but  perfectly  easy  and  well- 
known  words  is  much  greater  than  that  of  uttering  the  same 
syllable  over  again.  That  as  the  addition  progresses  we  have 
first  words  of  two  syllables  and  then  two  or,  at  most,  three  words 
of  three  syllables,  is  a  more  important  consideration.  The 
reagents  however  used  constantly  a  device  which  minimised 
the  difficulty;  emphasising  only  one  out  of  the  two  or  the 
three  syllables  to  be  spoken,  they  allowed  the  voice  to  die  away 
in  pronouncing  the  rest  of  the  word,  which  thus  formed  a  sort  of 
indistinct  sound  or  Nachklang.  That  this  diminished  intensity 
of  articulation  greatly  diminished  the  amount  of  disturbance 
otherwise  involved  seems  clear  from  the  cases  where  the  reagent, 
while  attending  too  exclusively  to  the  work  of  memorising, 
allowed  the  voice  to  die  away  and  ceased  to  speak  distinctly, 
thus  increasing  his  power  of  memorising.  The  only  data  of  an 
experimental  kind  available  for  the  confirmation  of  this 
account  of  the  matter  are  those  gained  in  the  course  of 
various  tentative  experiments.  The  purely  vocal  disturbance 
was  in  these  experiments  brought  about  by  pronouncing  in 

their  order  the  series  of  numbers  1,  2,  3, .  So  far  as  these 

experiments  go,  their  results  correspond  very  closely  to  what  is 
found  when  it  is  a  syllable  that  is  pronounced. 

Simple  as  the  act  of  addition  may  seem,  the  effort  required 
to  combine  it  with  the  process  of  memorising  was  extremely 
difficult — “painful”  was  the  term  applied  to  it  by  one  of  the 
subjects.  For  its  effect  was  to  make  it  almost  impossible  to  do 
more  than  stare  in  a  helpless  way  at  the  different  parts  of  the 
combination  of  letters  presented.  The  reagent  was  conscious  of 
the  presence  of  the  visual  objects,  but  it  was  as  if  their  meaning 
was  lost  and  he  was  unable  to  grasp  the  letters  as  anything 
more  than  mere  signs,  as  if  part  of  their  content  was  wanting. 
Accompanying  this  state  of  mind  was  a  feeling  of  helplessness, 
and  a  conviction  of  the  uselessness  for  the  purposes  of  learning 
and  recollection  of  this  merely  visual  consciousness  of  what  was 

5 


M. 


66 


W.  G.  SMITH  : 


presented.  According  to  one  observer  it  was  during  the  earlier 
and  easier  stages  of  addition  that  memorising  was  really  possible  : 
according  to  others  the  opportunity  for  grasping  the  connection 
of  letters  presented  itself  in  the  pauses  between  the  beats  of 
the  metronome,  or  at  the  close  of  the  time  of  exposure1,  when 
it  seemed  possible  as  it  were  to  snatch  part  of  the  series 
and  give  it  a  moment’s  concentration.  In  this  way  short 
groups  of  letters,  small  pictures,  could  be  impressed  on  the 
memory,  and  in  this  way  the  full  effect  of  the  distraction  was 
not  felt ;  the  attention  oscillated,  so  to  speak,  during  the  process 
of  memorising.  In  any  case  however  the  total  attention  together 
with  the  ability  to  reproduce  larger  groups  and  a  connected 
series  was  much  lessened.  How  low  the  value  of  the  memory 
would  have  sunk  had  the  state  of  distraction  involved  in 
each  separate  step  of  the  addition  been  maintained  uniformly 
throughout,  it  is  difficult  to  say. 

Reference  has  already  been  made  to  the  fact  that  as  we  pass 
to  the  second  and  then  to  the  first  group,  the  number  of  errors 
of  insertion  and  of  displacement  increases  relatively  to  the 
number  of  letters  actually  remembered.  As  regards  errors  of 
insertion  this  statement  seems  justified,  in  spite  of  considerable 
variations.  But  in  any  case  this  kind  of  error  is  not  of  great 
importance  in  comparison  with  the  errors  of  disorder:  they 
shew  with  considerable  clearness  and  persistency  an  increase 
from  the  fourth  group  to  the  first.  The  effect  of  mental 
distraction  may  then  be  said  to  consist  not  only  in  lessening  the 
total  area  of  consciousness  available  for  the  reception  of  new 
impressions,  but  in  confusing  the  recollection  and  thus  lessening 
the  power  of  forming  exact  associations,  which  shall  enable  the 
reagent  in  the  first  place  to  locate  definitely  what  has  been 
impressed  on  his  memory,  and  secondly  to  exclude  ideas  which 
did  not  form  part  in  the  complex  first  presented  to  him. 

In  his  research  on  the  Association  of  Successive  Ideas,  which 
has  already  been  referred  to,  Miinsterberg  comes  to  the  opposite 
conclusion.  In  these  experiments,  which  were  carried  out  in 
order  to  answer  the  question  whether  association  through  mere 
succession  was  possible,  letters  forming  series  of  varying  length 
were  successively  presented  to  the  subject.  Some  of  the  series 
were  learned  with  full  attention  ;  others  had  to  be  learned  while 
at  the  same  time  he  was  carrying  out  in  an  audible  voice 
complicated  arithmetical  operations.  The  distraction  of  the 
attention  lessened  the.  number  of  letters  wffiich  could  be 

1  The  latter  fact  was  noticed  only  when  the  electric  light  was  em¬ 
ployed.  It  is  difficult  to  say  whether  it  was  illusion,  or  was  due  to  the 
circumstance  that  the  cessation  of  light  in  the  incandescent  lamp  is  not 
quite  instantaneous. 


THE  RELATION  OF  ATTENTION  TO  MEMORY. 


67 


retained ;  according  to  Miinsterberg  it  could  not  be  the  reason 
why  in  series  including  only  four  or  five  letters  the  right  letters 
almost  without  exception  were  reproduced,  but  at  the  same  time 
were  given  in  wrong  order.  The  real  reason  lay,  he  contends,  in 
the  exclusion  of  any  opportunity  for  association  by  simultaneous 
contiguity.  “The  only  possible  effect  of  the  greater  or  less 
amount  of  attention  devoted  to  the  perception  of  single  letters 
is  to  cause  them  to  be  impressed  more  or  less  firmly  on  the 
memory.”1 

That  the  main  conclusion  regarding  successive  association — 
viz.,  that  apart  from  simultaneous  association  or  connections 
formed  by  means  of  the  motor  mechanism,  it  has  no  existence, — 
is  rendered  probable  may  be  granted.  But  it  does  not  follow 
either  from  the  theory  or  from  the  experimental  results  that 
the  only  effect  of  inattention  is  to  lessen  the  number  of  ideas 
which  can  be  retained ;  in  fact  the  suggestion  that  variation  in 
attention  can  vary  the  intensity  or  completeness  with  which 
ideas  are  “impressed”  on  memory,  without  at  the  same  time 
thereby  altering  the  intensity  or  strength  of  the  associative  bonds 
between  them,  seems  somewhat  improbable.  And  as  regards 
the  actual  results  obtained  in  Mtinsterberg’s  research  there  is 
room  for  the  working  of  all  these  factors ;  the  greatest  share  in 
the  disturbance  of  order  may  be  due  to  the  cause  he  suggests, 
but  part  also  may  very  well  be  due  to  the  two  factors  in 
attention ;  inattention  or  distraction  may  cause  fewer  ideas  to 
be  recollected,  and  may  lessen  the  strength  with  which  these 
are  held,  but  it  may  also  diminish  the  security  and  firmness  of 
their  associative  connections.  That  it  does  so  is  rendered 
highly  probable  by  the  results  which  have  already  been  brought 
forward  in  this  paper. 

The  words  Attention  and  Memory  have  been  used  through¬ 
out  these  pages  as  if  they  corresponded  to  definitely  and 
generally  accepted  conceptions.  Practically  we  know  quite 
well  what  attention  is,  though  the  theory  of  the  matter 
may  be  hard  enough.  It  will  be  most  profitable  here  to 
avoid  theories  and  simply  state  what  view  of  the  function  of 
attention  seems  most  appropriate  to  the  facts  which  we  have 
been  considering.  The  facts  relating  to  attention  are,  as  we 
saw,  furnished  mainly  by  the  experiments  of  the  first  group. 
And  the  chief  fact  we  found  to  be  that  inattention  not  merely 
lessened  the  extent  to  which  ideas  could  be  taken  up  and 
retained  in  consciousness,  but  in  a  still  greater  degree  confused 
and  deranged  the  associative  connections  in  what  was  actually 
recollected.  This  again  is  simply  the  objective  expression  for 

1  Zeitschr.  f.  Psych.,  i.  p.  105. 

5—2 


68 


W.  G.  SMITH  : 


the  subjectively  felt  inability  of  the  reagent  to  apperceive  and 
relate  what  was  presented  to  him.  Through  the  process  of 
mental  distraction,  said  one  of  the  observers,  Wahrnehmung  was 
turned  into  Empfindung. 

It  is  in  this  that  the  essential  operation  of  mental  distraction 
seems  to  lie.  In  ordinary  attentive  experience  each  impression, 
each  idea,  as  it  occurs,  is  met  and  transformed — to  speak  in 
Herbart’s  language — by  a  mass  of  apperceiving  ideas  which 
render  it  known,  familiar,  recognised,  and  in  doing  so  relate 
and  associate  it  with  similar  experience  we  have  had  in  the 
past.  It  is  this  mass  of  apperceiving  ideas  which  enables  us 
so  easily  without  conscious  or  voluntary  reflection  to  follow 
and  understand  some  new  fact  in  a  science  with  which 
we  are  familiar.  And  in  distraction  of  the  kind  we  are  con¬ 
sidering  the  really  effective  element  seems  to  be  an  inhibition 
of  these  associative  processes  which  enable  us  unconsciously 
to  relate  and  recognise  what  is  presented  to  us,  the  effect 
of  this  inhibition  being  to  produce  temporarily  a  state  to 
which  one  may  apply  the  term  Seelenblindheit.  How  far 
these  processes  are  in  any  case  represented  in  consciousness 
is  another  question ;  probably  hei;e,  as  in  many  other  relations, 
apperception  is  to  be  understood  as  referring  simply  to  the 
total  indefinite  state  or  attitude  of  mind,  “  the  feeling  of 
tendency”  resulting  from  the  minimal  excitation  of  certain 
“ideational  centres.”  The  essential  fact  in  attention  on  the 
other  hand  would  lie,  apart  from  its  accompaniments,  muscular 
adjustment  and  the  like,  in  the  strengthening  of  an  idea  or 
impression  by  the  processes  of  blending  and  redintegration, 
those  processes  which  are  operative  in  all  learning  and  knowing : 
attention  on  this  view  of  the  matter  would  be  knowledge  in  its 
most  perfect  form,  that  form  being  attained  not  merely  by 
positive  support  and  strengthening,  but  by  an  inhibition  or 
repression  of  all  that  might  compete  with  and  distract  energy 
from  the  apprehension  of  what  is  attended  to.  There  do  not 
seem  positive  reasons,  either  theoretical  or  experimental,  to 
forbid  the  hypothesis  that  there  are  degrees  of  clearness  and 
distinctness  in  mental  states:  it  seems  however  equally  im¬ 
possible  to  prove  that  an  apparent  increase  in  the  clearness 
of  an  idea  or  sensation  is  an  independent  special  process1,  and 

1  In  a  paper  “Uber  die  Schwankungen  in  der  Auffassung  minimaler 
Sinnesreize,”  Phil.  Stud.,  vm.  p.  365,  Eckener  asserts  that  a  stimulus 
can  still  affect  consciousness  though  quite  unperceived  and  “dark” :  his 
proof  consists  in  the  observation  that  when  a  minimal  sound  stimulus  has 
become  subjectively  inaudible,  the  reagent  is  still  in  many  cases  able  to  tell 
when  the  source  of  sound  is  objectively  interrupted.  That  this  proves 
nothing  in  regard  to  degrees  of  clearness  in  ideas  is  evident  when  we 


THE  RELATION  OF  ATTENTION  TO  MEMORY. 


69 


not  an  illusive  appearance  due  to  some  change  in  the  associative 
or  emotional  complex  surrounding  it. 

When  we  speak  of  memory  as  being  a  storehouse  for  ideas, 
of  psychical  states  impressing  themselves,  being  retained  and 
last  of  all  reproduced,  we  are  using  metaphors  which  are 
adequate  for  all  practical  purposes,  and  which  are  about  as 
true  as  the  theories  often  brought  forward  as  giving  the  real 
truth  of  the  matter.  On  this  subject  Physiology  seems  a 
better  guide  than  Psychology,  for  Psychology  has  been  too 
much  burdened  by  its  theory  of  ideas,  and  by  its  conviction 
that  the  elementary  and  fundamental  psychical  processes  must 
be  explained  in  terms  of  the  developed  mind.  Physiological 
memory  means  simply  that  a  given  nervous  centre  has  been  so 
changed — how  we  do  not  know — by  the  occurrence  in  it  of  a 
certain  set  of  processes,  that  when  one  of  these  occurs  again 
the  others  tend  to  follow.  It  does  not  occur  to  anyone  to  say 
that  the  old  processes  are  reproduced,  and  that  physiological 
memory  is  inconceivable  unless  we  suppose  that  numberless  old 
innervations  fuse  with  a  new  one,  when  that  new  one  occurs, 
and  so  enable  it  to  start  a  series  of  movements  over  again.  But 
it  does  occur  to  psychologists,  and  is  confidently  asserted,  that 
such  a  fusion  of  old  and  new  is  one  of  the  fundamental 
associative  processes.  The  physiological  account  of  the  matter 
is  simple  and  natural :  old  psychical  states  are  no  more 
reproduced  than  are  physical  states,  but  similar  states  are 
reproduced ;  these  in  their  turn  tend  to  recall  other  states, 
which  again  had  something  like  them  in  past  experience.  The 
fusion  of  old  and  new  which  occurs  in  organic  memory  means  that 
owing  to  habit  or  repetition  of  an  experience  the  physiological 
processes  have  become  changed :  they  are  modified  owing  to 
what  has  gone  before,  so  that  a  fresh  reaction  is  correspondingly 
modified.  There  seems  no  reason  why,  when  we  speak  of  storing 
up  and  of  reproduction  of  ideas,  we  should  introduce  anything 
more  into  the  processes  than  we  would  require  were  we  to 
apply  like  metaphors  to  purely  physiological  memory. 

According  to  the  usual  statement  of  the  Law  of  Association 
by  Simultaneous  Contiguity,  objects  or  ideas  which  have  once 
been  present  together  in  consciousness  tend  in  consequence  to 
recur  in  the  same  connection.  It  is  obvious  that  in  such 
statements  emphasis  is  laid  on  the  fact  that  the  ideas  have 
been  simultaneously  elements  of  a  conscious  state,  and  that  the 
process  is  one  concerned  solely  with  sensory  or  intellectual 

remember  that  cessation  of  a  stimulus  physiologically  may  have  for  its 
first  effect  an  increase  of  the  reaction  ;  e.g.,  in  experiments  demonstrating 
the  electrical  response  of  the  frog’s  eye  to  light,  the  first  effect  noted  when 
the  light  is  withdrawn  is  an  increase  of  the  response. 


70 


W.  G.  SMITH  : 


experience.  Observations  made  during  the  course  of  this 
research  give  occasion  for  some  remarks  on  these  two  points. 

It  was  pointed  out  again  and  again  by  the  reagents  that 
mere  perception  of  a  number  of  letters,  mere  presence  together 
in  consciousness,  was  useless  for  the  purpose  of  associating  and 
learning ;  that  unless  they  were  able  systematically  to  go 
through  the  series  at  a  moderate  speed  and  with  a  fair  amount 
of  attention,  no  abiding  impression  was  left  on  the  memory. 
And  the  remark  suggested  by  these  observations  is  that  those 
factors  which  form  the  real  constructive  basis  of  associations 
are  such  as  are  usually  recognised  merely  as  helps  and  supports 
to  a  connection  which  is  due  to  simultaneous  apperception. 
Interest,  Attention,  Repetition  are  recognised,  though  only  as 
modifying  factors,  as  influences  which  contribute  to  the  efficacy 
of  contiguity.  But  it  is  obvious  that  Interest  in  itself  has  no 
necessary  connection  with  and  is  not  implied  in  contiguity: 
Attention  again  is  a  factor  which  as  we  have  seen  is  of  great 
importance  in  the  processes  of  associating  and  recollecting 
ideas ;  but  that  too  is  not  implied  in  the  description  commonly 
given  of  the  nature  of  association  by  contiguity.  And,  so  far  as 
the  need  of  Repetition,  Exercise,  Habit  for  the  formation  of 
firm  associative  connections  is  emphasised,  it  is  admitted  that 
mere  simultaneity  is  of  little  avail.  It  may  well  be  that  the 
method  of  entering  into  one’s  breast  and  observing  what 
happens  in  the  play  of  ideas  whose  connections  have  already 
been  formed,  has  been  the  reason  why  a  description  which 
applies  to  so  many  of  our  actual  associations  is  taken  as  a 
statement  of  the  law  of  their  formation  and  growth :  that 
description  is  here  taken  for  explanation  seems  in  any  case  to 
be  the  fact.  Ideas  which  are  associated  have  very  often  been 
contiguous ; — on  the  other  hand  ideas  which  have  been  merely 
contiguous  are  in  the  vast  majority  of  cases  not  associated. 
Contiguity  is  indeed  a  formal  characteristic  which  associated 
ideas  possess  :  it  seems  necessary  that  ideas  should  form  parts  of 
one  conscious  state  before  they  can  be  associated.  It  is  however 
in  these  dynamic  factors,  Interest,  Attention,  Repetition,  that 
the  real  causes,  the  formative  influences,  are  found;  it  is  this 
which  should  form  the  matter  of  any  law  intended  to  state  the 
nature  of  the  processes  by  which  our  actual  assqciative  connec¬ 
tions  are  built  up. 

The  second  set  of  facts  points  to  the  need  of  emphasising, 
in  our  account  of  Association  by  Contiguity,  the  part  played  by 
the  agency  of  the  motor  system.  That  habitual  activities,  or 
any  acquired  physical  ability,  illustrate  the  operation  of  con¬ 
tiguity  has  long  been  recognised.  But  in  order  to  understand 
the  formation  of  associative  connections  in  the  more  purely 


THE  RELATION  OF  ATTENTION  TO  MEMORY. 


71 


sensory  or  intellectual  sphere,  it  seems  necessary  here  also  to 
seek  an  explanation  in  the  functions  of  the  motor  mechanism. 
How  that  operates  may  not  be  clear;  the  subject,  whose 
importance  has  been  recognised  perhaps  most  by  Bain,  Strieker 
and  Miinsterberg,  has  not  been  studied  with  sufficient  exactness 
either  psychologically  or  physiologically.  But  this  factor  offers 
itself  without  straining  as  a  reason  why  visual  objects  presented 
in  succession  should  refuse  to  relate  themselves  as  members  of  a 
series  when  the  help  of  articulatory  innervations  is  withdrawn, 
and  why  the  reagents  in  these  experiments  insisted  so  strongly 
on  the  necessity  of  going  over  the  letters  serially  and  systemati¬ 
cally,  and  on  the  great  hindrance  caused  by  disturbance  of  the 
vocal  mechanism.  These  facts  it  would  seem  cannot  be  explained 
except  by  supposing  that,  as  purely  sensory  objects,  the  associa¬ 
tive  tendency  of  the  presentations  was  much  less  strong  than 
where  the  reagent  was  left  free  to  combine  both  sensory  and 
motor  elements  in  the  process  of  memorising.  And,  if  this  be 
so,  it  will  only  be  the  psychical  expression  for  the  conviction 
which  is  gaining  ground  in  Physiology  that  there  are  no  purely 
sensory  nervous  centres,  but  that  what  bears  this  name  really 
subserves  a  double  function. 

Miinsterberg,  in  the  paper  from  which  I  have  already 
quoted,  states  that  no  special  or  predominant  type  of  in¬ 
correct  order  was  detected  in  the  answers  which  were  given 
in  his  experiments.  Bolton1,  experimenting  on  school-children 
to  whom  he  read  over  lines  of  five  to  eight  figures,  found 
that  among  the  errors  that  of  inversion  was  prominent. 
Errors  of  inversion  were  not  infrequent  in  the  experiments 
already  described ;  still  the  number  was  not  at  all  remarkable. 
Another  type  of  error  which  occurred  fairly  often  is  more  inter¬ 
esting  ;  it  consisted  in  letters  changing  their  places  in  the  lines 
so  that,  for  example,  the  first  letter  of  one  line  would  take  the 
place  of  the  corresponding  letter  in  another,  this  second  letter 
then  occupying  the  place  of  the  first ;  in  another  instance  the 
first  letter  of  the  last  line  is  followed  by  the  second  of  the 
middle  line,  by  the  third  of  the  last  line,  and  then  by  the 
fourth  of  the  middle  line.  Whether  this  is  to  be  interpreted 
as  a  disarrangement  of  a  visual  picture  it  is  impossible  in  the 
absence  of  direct  experiments  to  say.  The  question  still  waits 
solution,  what  sort  of  error  is  committed  when  each  element  in 
memory,  visual  sensations,  auditory  sensations  and  so  on,  is 
isolated  and  its  capabilities  tested.  To  such  a  task  the  method 
applied  in  this  investigation  seems  specially  fitted. 

1  The  Growth  of  Memory  in  Schoolchildren.  Am.  Journ.  of  Psych ., 

v.  p.  363. 


72 


W.  G.  SMITH  : 


The  number  of  cases  where  similar  letters  were  confused  was 
too  great  to  allow  of  the  supposition  that  the  confusion  was  due 
to  accident :  it  was  however  not  great  enough  to  allow  of  a 
definite  account  of  this  tendency.  Letters  similar  in  sound, 
such  as  m  and  n,  or  t  and  d,  were  interchanged :  similarity  in 
shape  seemed  to  be  the  reason  why  h  and  k ,  u  and  v  were 
confused.  It  may  well  be  that  with  such  letters  as  t  and  d,  the 
reason  of  the  interchange  lay  also  in  the  easy  transition  from 
the  one  position  of  the  vocal  organ  to  the  other.  What  letters 
are  most  liable  to  confusion  and  what  disappear  most  readily, 
together  with  the  relation  of  these  facts  to  the  phenomena  of 
aphasia1,  are  matters  of  interest,  but  can  be  studied  only  by 
extended  and  precise  experiment.  A  series  of  experiments  was 
begun  to  test  what  effect  audible  pronunciation  of  the  letters  to 
be  learned  had  upon  the  memory :  it  was  however  only  carried 
far  enough  to  shew  that  probably  very  great  individual  differ¬ 
ences  exist  in  regard  to  the  help  or  hindrance  which  such 
express  articulation  occasions  in  the  effort  to  memorise. 

It  is  plain  that  one  great  drawback  in  the  results  gained 
first  by  Ebbinghaus,  and  next  by  Muller  and  Schumann,  in  their 
investigations  on  memory,  is  that  the  work  of  memory  is 
formulated  in  terms  of  time  only,  and  that  a  qualitative 
analysis  of  memory  is  still  to  seek.  It  is  obvious  that 
results  into  which  visual,  auditory,  motor  and  other  elements 
enter  as  unknown,  though  probably  relatively  constant  factors, 
can  form  only  the  first  step  in  an  account  of  memory.  WTe 
have  still,  as  was  pointed  out  before,  to  find  out  the  capabilities 
of  these  various  factors  and  to  shew  further  what  changes 
they  undergo  in  the  gradual  decay  of  memory.  A  few  observa¬ 
tions  regarding  the  various  factors  may  be  adduced  from  the 
foregoing  experiments.  In  the  experiments  of  the  last  group 
the  memory  image  seemed  to  be  a  somewhat  indefinite  complex 
of  various  factors :  as  the  distracting  activity  became  more 
difficult,  and  the  aid  given  by  articulatory  innervations  grew 
less,  the  observer  had  to  depend  more  and  more  on  the  visual 
consciousness.  Auditory  ideas,  as  is  intelligible,  came  little 
into  play :  they  were  indeed  said  to  be  present,  but  it  is 
doubtful  whether  sensations  connected  with  the  organ  of 
speech  were  not  mistaken  for  them,  a  confusion  which  seems 
particularly  easy  when  the  two  elements  are  present  only  in 
imagination  or  memory.  Motor  elements  seemed  to  be  present 
in  the  process  of  learning  wherever  they  were  not  expressly 
excluded:  it  was  they  that  lasted  longest  and  enabled  the 

1  It  might  be  possible  also  to  establish  some  relation  between  such 
changes  and  the  philological  facts  embodied  in  “  Grimm’s  Law.” 


THE  RELATION  OF  ATTENTION  TO  MEMORY. 


73 


reagent  to  recollect  when  the  other  sensory  images  failed.  It 
is  not  without  interest  to  note  the  different  modes  of  reproduc¬ 
tion  of  these  elements.  Whereas  with  the  sensory  memory 
the  reagent  seemed  expressly  to  perceive  and  recognise  each 
successive  idea  that  appeared  in  consciousness,  the  process  in 
motor  memory  was  automatic  or  mechanical.  The  reagent 
pronounced  the  letters  because  an  impulse  to  speak  presented 
itself ;  often  the  appropriate  movements  came  one  after  the  other 
without  thought  or  reflection,  and  without  their  being  recognised 
as  forming  the  required  elements  in  the  complex  that  was  to 
be  recollected1.  In  some  cases  what  was  retained  in  memory 
was  only  a  vague  general  idea  of  the  geometrical  shape  of  the 
letters — their  curves  or  straight  lines — which  on  reflection  might 
become  more  definite :  in  other  instances  there  seemed  to  be  a 
sort  of  vague  idea  of  the  spatial  arrangement  of  the  letters 
without  any  definite  observable  images  being  present.  It  often 
happened  that,  when  the  reagent  believed  himself  to  be  in  full 
possession  of  a  line  and  ready  to  repeat  it  perfectly,  he  was  yet 
unable  when  the  time  came  to  reproduce  any  part  of  it :  to  his 
surprise  the  line  simply  disappeared.  Apparently  this  often 
happened  while  he  was  engaged  in  repeating  the  first  letters : 
during  this  effort  the  rest  of  the  memory  image  seemed  to  be 
driven  out  of  consciousness.  What  the  conditions  of  such  a 
belief  and  its  subsequent  effects  are,  could  not  be  exactly 
determined :  according  to  one  observer  K.  the  basis  was  a 
Gesammtvorstellung,  a  sort  of  all-embracing  complex  idea  in 
which  the  parts  have  an  indefinitely  felt  unity. 

1  Observations  of  similar  phenomena  are  given  by  Muller  and  Schumann4 
loc.  cit.  §§  23  ff. 


